This invention relates to a pour spout fitment, a method in which the pour spout fitment is attached to packaging material, a combination of the pour spout fitment and the packaging material, and a method of opening the same.
A wide variety of pour spout fitments for packaging cartons are known.
Some of these known fitments include pour spouts which are inserted on the insides of the cartons through holes formed through panels of the cartons, so that pouring rims of the pour spouts project outwardly through the holes and flanges of the pour spouts are sealingly attached to portions of the inside surfaces of the carton panels round the peripheries of the holes. Such pour spout fitments can instead be inserted through, and sealed round, holes through carton blanks from which the cartons will be formed, for example on a form-fill-seal packaging machine. Generally, these types of pour spout fitments are attached before the cartons are filled.
Other known pour spout fitments are applied to the outsides of the carton blanks or cartons, around pouring holes formed through the panels. It is known to attach these types of pour spout fitments to the cartons either before filling or after filling.
It is conventional for pour spout fitments to be attached to packaging material in the form of a laminate consisting of paperboard coated on both faces with thermoplastics, particularly low density polyethylene (LDPE). It is also conventional for the packaging material to include, to the inside of the paperboard, a gas barrier layer, such as aluminium foil or ethylene vinyl alcohol (EVOH).
It is also known, with those types of pour spout fitments which are attached to the outsides of the packaging material, for the pour spouts not to encircle holes but to encircle barrier-forming discs of material, which may be that of the carton walls themselves or pieces of barrier film or foil closing the holes in the carton walls. The discs of material of the carton walls may be bounded by partial-depth cuts in an attempt to ensure that the carton opens more easily.
The pour spouts of the fitments are externally closed by screw caps, flip-tops, or flaps.
U.S. Pat. No. 4,813,578 discloses a plastics pour spout construction particularly adapted for longer shelf-life barrier paperboard containers, such as containers of the gable-top type, the interior surfaces of the containers being lined with a major barrier layer. A dispensing opening is formed through the paperboard and the major barrier layer extends across and covers this opening. An externally threaded pour spout, sealed to a polyethylene minor barrier layer of the container, carries a screw cap which normally closes the pour spout. This cap has integral therewith an inner annular skirt the lower edge of which is adhered to that portion of the minor barrier layer which spans the dispensing opening. When the cap is unscrewed from the spout, the skirt carries part of the overall barrier away from its normal position closing the opening, thus rupturing the overall barrier and permitting dispensing of the contents of the container. The dispensing opening is usually die-cut prior to extrusion of the minor barrier layer of LDPE onto the exterior surface of the paperboard and prior to the placement on the internal surface of the paperboard of the major barrier layer, which may be a single layer of, for example, xe2x80x9cSURLYNxe2x80x9d, a metallic foil, polyethylene, or other material. Alternatively, the major barrier may be in the form of layers of two or more difference materials. The inner end of the skirt is adhered to the external surface of the LDPE layer in the dispensing opening by means of heat and pressure. The pour spout fitment relies upon strong adhesion between the skirt and the LDPE layer and between the LDPE layer and the major barrier layer for opening of the dispensing opening upon unscrewing of the cap. Rupture of the overall barrier is effected not only by axially outward movement of the skirt, but also by the rotation of the skirt relative to the pour spout and the container upon the initial unscrewing of the screw cap. Re-closing of the container, in the event that all of the contents have not been dispensed upon the initial opening, is effected by simply screwing the cap back on, although the barrier properties of the container are lost owing to the rupture of the overall barrier. The force required to rupture the overall barrier indicates to the consumer that the package has not been tampered with. In addition, the ruptured state of the overall barrier lends visual proof of tampering. Although it is preferred that the pour spout fitment should be applied to a container having an external layer of polyethylene, that layer may be omitted and some other adhesive then take the place of that layer for joining the major barrier to the inner edge of the skirt and for joining the pour spout to the paperboard wall. The screw cap may have its outer skirt omitted and, instead, interengaging screw threads be located between the inner skirt and the pour spout.
EP-B-0328652 discloses a plastics pour spout fitment in which a pour spout either extends through a hole through a carton wall and has its flange sealed to the inside of the wall, or has its flange sealed to the outside of the wall around a pouring port sealed with a film. In the former case, the inner end of the pour spout is sealed with a film. Within the pour spout is a tubular plunger formed at its inner end with a ring of downwardly projecting teeth which are interrupted at two diametrically opposite locations. Various embodiments of the fitment are disclosed. In certain embodiments, the plunger has two camming faces arranged at an angular pitch of 180xc2x0 and extending outwardly to the outer end of the plunger. The two camming faces co-operate with respective downwardly-directed camming faces formed around the outside of an inner skirt of a screw cap arranged to be screwed onto the pour spout. Ratchet teeth formed on the inner peripheral surface of the pour spout co-operate with ratchet teeth formed on the outer peripheral surface of the plunger so as to produce rotation of the plunger with the screw cap during screwing of the screw cap onto the pour spout, but so as to prevent rotation of the plunger with the screw cap upon unscrewing of the latter. With the pour spout fitment sealed to the carton, unscrewing of the cap causes the plunger to displace axially inwards so that the teeth thereon pierce and break the film. Continued outward displacement of the cap opens the pour spout, leaving the plunger in its innermost position. Since the plunger remains in the pour spout, it reduces the through-flow cross-sectional area thereof.
U.S. Pat. No. 5,147,070 discloses a pour spout fitment in which a screw cap is removed and then, with a fingertip, a consumer pushes inwards a plunger formed at its inner end with a ring of teeth. Again, the plunger remains in the pour spout opening during pouring and thus restricts the through-flow cross-section thereof and, moreover, the use of a finger is unhygienic. U.S. Pat. No. 4,483,464 discloses a plastics, similar pour spout fitment.
GB-A-2210359 discloses a plastics pour spout fitment for a carton the wall structure of which includes a gas barrier layer. A gas barrier film is provided across the inner end of a pour spout of the fitment, and the gas barrier layer and the gas barrier film are overlapped or continuous when viewed axially of the fitment, to maintain gas barrier properties for the carton. In one version, the pour spout is connected via integral bridges to a disc integral with a ringpull inside the pour spout and adhered to the gas barrier film, the intention being that outward pulling of the ringpull breaks the disc away from the pour spout and thus breaks away from the remainder of the gas barrier film the part thereof adhered to the disc. The breaking-away of the relevant part of the film relies upon strong adhesion between the disc and film. Moreover, opening of the pour spout requires at least a finger to be inserted into the spout to engage the ringpull. In another version, unscrewing of a screw cap upon the pour spout causes an externally threaded inner skirt of the cap to screw downwards a tubular plunger formed with a ring of teeth at its inner end and guided by keys in longitudinal slots in the inner peripheral surface of the pour spout. Again, the plunger remains in the pour spout after opening and so constricts the through-flow cross-sectional area thereof.
U.S. Pat. No. 5,141,133 discloses a plurality of differing versions of pour spout fitment, in one of which an axially guided tubular plunger formed with a ring of teeth at its inner end breaks through a synthetic resin film closing a pouring opening through a paperboard wall, and in another version of which a blade at the inner end of a tubular plunger breaks away and pushes aside a disc defined by an annular score in the external surface of a container wall consisting of a paper layer with synthetic resin films laminated to respective opposite sides of the paper layer. In both of these versions, the plunger remains in its innermost position in the pour spout after opening.
EP-A-0385603 discloses a pour spout fitment in which a roof panel of a gable-top carton formed from a paper layer provided on respective opposite surfaces with thermoplastic resin layers has a slot of open-loop form punched therethrough, leaving a non-punched portion at the top of the loop. A barrier film, such as aluminium foil, is attached at the inner surface of the panel so as to cover the slot. A pour spout of a pour spout fitment is sealed to the outer surface of the panel around the slot and has connected integrally therewith via frangible bridges a tubular plunger formed at its inner end with teeth. The pour spout is closed by a screw cap. To open the carton, the screw cap is removed and the plunger pressed inwards by a consumer so that the ring of teeth enter the slot and break through the barrier film, causing the panel disc within the slot to turn inwards about the non-punched portion.
According to one aspect of the present invention, there is provided a pour spout fitment, comprising a pour spout having a longitudinal axis and adapted to be attached to packaging material, and a plunger in said pour spout and displaceable inwards along said axis relative to said pour spout to displace inwards a portion of said packaging material closing an inner end of the pour spout, characterized in that, following the inward displacement of the plunger, the plunger is displaceable outwards along said axis relative to said pour spout to beyond said pour spout and in that an inner end of said plunger is adapted to be attached to said portion of said packaging material, whereby the outward displacement of said plunger to beyond said pour spout would be accompanied by outward displacement of said portion to beyond said pour spout.
According to another aspect of the present invention, there is provided in combination,
packaging material, and
a pour spout fitment, comprising a pour spout having a longitudinal axis and attached to said packaging material, and a plunger in said pour spout and displaceable inwards along said axis relative to said pour spout to displace inwards a portion of said packaging material closing an inner end of the pour spout, characterized in that, following the inward displacement of the plunger, the plunger is displaceable outwards along said axis relative to said pour spout to beyond said pour spout and in that an inner end of said plunger is attached to said portion of said packaging material, whereby the outward displacement of said plunger to beyond said pour spout is accompanied by outward displacement of said portion to beyond said pour spout.
According to a third aspect of the present invention, there is provided a method comprising
attaching to packaging material a pour spout of a pour spout fitment so that said pour spout extends round a portion of said material, said pour spout having a longitudinal axis,
characterized by, prior to said attaching, forming a ring of weakness round said portion, and
attaching to the outer surface of said portion a plunger of said pour spout fitment.
According to a fourth aspect of the present invention, there is provided a method comprising providing packaging material to which is attached a pour spout fitment, with a plunger of said fitment being attached to a portion of said material and a pour spout of said fitment being attached to portions of said material around said portion, detaching said portion from said portions by a procedure comprised of displacing said plunger inwardly along an axis of said fitment to cause said plunger to press against said portion, and withdrawing said plunger and thus said portion outwardly from said pour spout.
Owing to the present invention, it is possible to open a pouring opening in packaging material with a reasonably high degree of certainty, with complete removal of the packaging material part previously closing the opening, so that that part does not thereafter obstruct pouring, and with the plunger being removed so as not to obstruct the pour spout or the pouring opening.